Pressure sensitive adhesive compositions comprising a curable polymer combined with a tackifier resin are well known in the art.
Pressure sensitive adhesive compositions comprising a hydrolyzable silyl group-containing oxyalkylene polymer among such curable polymers and a tackifier resin can be applied for coating using no organic solvent or using almost no organic solvent and therefore have been proposed as pressure sensitive adhesive compositions exerting no adverse influences on the environment (cf. e.g. Japanese Kokai Publication Sho59-71377). When a hydrolyzable silyl group-containing oxyalkylene polymer is used, such characteristics as affinity for various adherends, hydrophilicity and chemical stability owing to the chemical structure of this polymer, in particular, can be manifested and therefore investigations have been made to extend the range of application of such polymer to various fields, including repeeling, among others. However, the pressure sensitive adhesive compositions mentioned above are unsatisfactory in characteristics required of pressure sensitive adhesives, for example in adhesive strength and holding ability upon sticking to curved surfaces. Further, when a tackifier resin is used in large amounts to increase the adhesive strength, such good characteristics of the oxyalkylene polymers as affinity for various adherends, hydrophilicity and chemical stability, are sacrificed.